Small mountain or low mountain?

Solution 1:

A specific geological formation bridging the gap between ordinary hills and full-fledged mountains (and pleasant to hike):

• foothills

They are a transition zone between plains and low relief hills to the adjacent topographically higher mountains, hills, and uplands...Foothills primarily border mountains...Another word for a foothill region is piedmont, characterized by relatively low, rolling hills with heights above sea level between 200 feet (50 m) and 800 feet to 1,000 feet (250 m to 300 m)... Essentially, the Piedmont is the remnant of several ancient mountain chains that have since been eroded away.

Piedmont and foothills (or foot-hills) are essentially the same thing geographically, although foot-hill is rooted in Old English, while piedmont is from Old Italian.

First known use of foothill: 1788

Some of the hikes are in the foothills and some are in the lower slopes of the mountains.

Solution 2:

I agree that essentially "short mountain" and "low mountain" are synonymous, but there are a few connotations associated with both.

As far as I understand it, it really depends on the context of the mountains you're describing. "Short" tells us that there may be taller mountains nearby, and its slope may be steeper than a typical foothill. A "low" mountain would be one that has an easier slope, and is usually surrounded by similarly low mountains, but is still taller than a foothill.

If you can point out a low mountain among a mountain range, I'd go for "short", but if it's an average short mountain among many, you can use "low". I hope that's clear! :)